doc: CategoryService javadocs

src/main/java/com/application/munera/services/CategoryService.java

@@ -18,31 +18,71 @@ public class CategoryService {
         this.categoryRepository = categoryRepository;
     }
 
+    /**
+     * Finds a category by its ID.
+     *
+     * @param id the ID of the category to find
+     * @return an {@code Optional} containing the found category, or {@code Optional.empty()} if no category with the given ID exists
+     */
     public Optional<Category> findById(Long id) {
         return categoryRepository.findById(id);
     }
 
+    /**
+     * Finds all categories associated with a specific user ID.
+     *
+     * @param userId the ID of the user whose categories are to be retrieved
+     * @return a {@code List} of categories associated with the given user ID
+     */
     public List<Category> findAllByUserId(Long userId) {
         return categoryRepository.findByUserId(userId);
     }
 
+    /**
+     * Updates the provided category and associates it with a specific user ID.
+     *
+     * @param category the category to update
+     * @param userId the ID of the user to associate with the category
+     */
     public void update(Category category, Long userId) {
         category.setUserId(userId);
         categoryRepository.save(category);
     }
 
+    /**
+     * Deletes the given category.
+     *
+     * @param category the category to delete
+     */
     public void delete(Category category) {
         categoryRepository.delete(category);
     }
 
+    /**
+     * Retrieves a paginated list of categories.
+     *
+     * @param pageable the pagination information
+     * @return a {@code Page} containing the categories for the requested page
+     */
     public Page<Category> list(Pageable pageable){
         return categoryRepository.findAll(pageable);
     }
 
+    /**
+     * Counts the total number of categories.
+     *
+     * @return the total number of categories
+     */
     public Long count() {
         return this.categoryRepository.count();
     }
 
+    /**
+     * Saves the given category to the repository.
+     *
+     * @param category the category to save
+     * @return the saved category
+     */
     public Category save(Category category) {
         return this.categoryRepository.save(category);
     }